stuck Posted February 6, 2012 Share Posted February 6, 2012 Gents, I have the standard temp gauge in my 2000 110 hooked up to the 4.6's sender causing the gauge to read incorrectly. To sort this out is my only option to find an older style gauge from a V8 90 or 110? I have considered screwing a Td5 sensor into the V8 but I'm not sure of the running temperatures of a diesel. Ta, Mick. Quote Link to comment Share on other sites More sharing options...
tacr2man Posted February 6, 2012 Share Posted February 6, 2012 the sender in the 4.6 might not be the same as in 90/110 V8 as that engine was never fitted . Either way you need to match sensor and guage , the running temp wont be that different anyhow so will be in operating range of either set up HTSH Quote Link to comment Share on other sites More sharing options...
Dave W Posted February 6, 2012 Share Posted February 6, 2012 Assuming it reads high at the moment like my 3.9 did when I was using a TD5 gauge, all you need to do is put a variable resistor between the sender and the gauge and you can adjust it so it reads centrally at the normal operating temperature. The TD5 gauge range is different form the V8 one in that it deflects more from the centre when the temperature moves either way. Somewhere i have the calculations I made by comparing the V8 sensor with a TD5 sensor in a pan of hot water but if you get a 0-100 ohm variable resistor it'll cover the range required. Once it's set, assuming you use a trimmer style resistor, a blob of nail varnish will lock it into position and you can forget about it. Quote Link to comment Share on other sites More sharing options...
stuck Posted February 6, 2012 Author Share Posted February 6, 2012 Excellent tip! Cheers for that Dave. Quote Link to comment Share on other sites More sharing options...
PieEater3142 Posted February 7, 2012 Share Posted February 7, 2012 I have a TD5 guage and a 200tdi engine (project so not yet running) - do I need to swap out the temp sensor? If so what one do I need? Quote Link to comment Share on other sites More sharing options...
Retroanaconda Posted February 7, 2012 Share Posted February 7, 2012 You need the late 300Tdi sensor/sender unit, part number AMR1425. This is a 1/8" NPT thread, so will need an adaptor for the 200Tdi (which is 5/8" UNF). I'm not familiar with the V8, but if it is a different thread then there should be an adaptor available to take it to the 1/8" NPT for the sender. Then the signal needs to either be trimmed with a resistor as above, or you can pass it through the speedo head where the adjustment is done for you. You want the wire that goes to the sender unit to go into pin 5 and the wire to the gauge to go into pin 9, both on the lower speedometer plug. See this PDF for details, you should be able to follow the wires (red) to see what I mean. http://www.retroanaconda.com/james/cars/defender/td5_gauges/Gauges%20Wiring%20Diagram.pdf Quote Link to comment Share on other sites More sharing options...
Mo Murphy Posted February 7, 2012 Share Posted February 7, 2012 AMR1425 was used in some V8s too. HTH Mo Quote Link to comment Share on other sites More sharing options...
PieEater3142 Posted February 7, 2012 Share Posted February 7, 2012 thanks western Quote Link to comment Share on other sites More sharing options...
western Posted February 7, 2012 Share Posted February 7, 2012 but I haven't replied to this thread before now, think you mean Thanks Mo. Quote Link to comment Share on other sites More sharing options...
Boris113 Posted February 7, 2012 Share Posted February 7, 2012 Dad's 90 has a 3.9 with a TD5 dash/clocks, IIRC that has a variable resistor in it. I don't know anymore than that, just that I asked the previous owner how he got the 2 to match up. Harry Quote Link to comment Share on other sites More sharing options...
PieEater3142 Posted February 8, 2012 Share Posted February 8, 2012 Damn it, apologies Mo. So used to western having the answer. ... Quote Link to comment Share on other sites More sharing options...
zim Posted February 8, 2012 Share Posted February 8, 2012 Dave, surely if you do that the gauge will be variably wrong though ? i.e. only correct at the middle. Can you not take out the actual gauge and fit a new 52mm gauge available from most places ? G Quote Link to comment Share on other sites More sharing options...
Retroanaconda Posted February 8, 2012 Share Posted February 8, 2012 Yes, using a fixed resistance is a little bit of a bodge since the gauge is not linear in its operation. Routing it through the speedo solves this problem, the electronics inside perform the required adjustments. This is the way Land Rover do it on the rest-of-world spec. vehicles that were fitted with Td5 dashboards and 300Tdi engines. Quote Link to comment Share on other sites More sharing options...
zim Posted February 8, 2012 Share Posted February 8, 2012 Just been looking at your diagram, looks good It's strange seeing an NPT thread on a LR AMR1425 is listed as : TEMPERATURE SENDER SWITCH DISCOVERY S1 2.0 MPI - 2.5TDI - 200 TDI - 300 TDI - V8 RANGE ROVER CLASSIC 2.5TDI - 200 TDI - 300 TDI - V8 RANGE ROVER P38 V8 1995 - 1996 TO VIN TA346793 On my 4.2 it isn't 1/8npt, from memory 5/8 unf iirc. Edit : Which come to think of it, this'll be what Mick already has in the engine. Just needs to route his cables through the dash as instructed in your diagram G Quote Link to comment Share on other sites More sharing options...
Retroanaconda Posted February 8, 2012 Share Posted February 8, 2012 It's definitely that sender that the circuitry in the speedo head is designed to work with. using the other 300Tdi sender (black top one) gives erroneous readings. I have the AMR1425 in my 90 with Td5 gauge etc. and it reads just left of vertical as normal running temperature. Just like the old 200Tdi gauge used to do, except that I can read this one at night Quote Link to comment Share on other sites More sharing options...
Quagmire Posted February 8, 2012 Share Posted February 8, 2012 Both mine and my dads V8's have the td5 dash mod by retroanaconda, we used the 300tdi sender as it is listed for the 50th's too (i think) normal running temp sits a tiny fraction to the left of vertical on both. We drilled out an original sender and tapped to take the smaller new sender.. posting from phone so good that makes sense... Quote Link to comment Share on other sites More sharing options...
Mo Murphy Posted February 8, 2012 Share Posted February 8, 2012 Damn it, apologies Mo. So used to western having the answer. ... No problem but I think it's James that deserves the credit Mo Quote Link to comment Share on other sites More sharing options...
Dave W Posted February 8, 2012 Share Posted February 8, 2012 Dave, surely if you do that the gauge will be variably wrong though ? i.e. only correct at the middle. The gauge is only a guide, not sure what you think it would be telling you when it's not in the centre ? The TD5 gauge responds to a similar resistance range to the V8 gauge it's just offset relative to the V8 gauge. All the resistor does is bring the TD5 gauge into the same calibration as the sensor. You have to realise that the gauges only operate over a relatively small window of temperatures. The centre "normal" part of the gauge only shows around a 30 degree or less range. Centering the gauge around your normal operating temperature gives you the same range either side as the sensors aren't that different in terms of resistance change per degree centigrade when they are at around the 80 degree mark. Neither the gauges nor the senders operate in a linear fashion. Quote Link to comment Share on other sites More sharing options...
stuck Posted February 8, 2012 Author Share Posted February 8, 2012 Thanks very much for all the replies gent's, much appreciated. Big thank you to Retroanoconda for posting the speedo trick, will do that at the weekend. Any bodges tricks for getting a RRC fuel level sender to work with the Td5 dash? New gauge time? Quote Link to comment Share on other sites More sharing options...
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